Device for controlling the gas medium inside a container

Abstract

A device for controlling the composition inside a shipping / storage container for produce, such as bananas, is disclosed. Such atmospheric control is particularly important when dealing with the ripening of respiring fruit. The device comprises a chamber surrounded by an outer wall, at least a portion of that wall made up of a selectively gas-permeable membrane which is in communication with the outside atmosphere. The chamber also includes at least two channels which are connected to the container: one which transmits gas form the chamber to the container, and one which transmits gas from the container to the chamber.

Description

[0001] This application is based upon and claims priority from U.S. Provisional Patent Application No. 60 / 697,722, Fernandez et al., filed Jul. 8, 2005, incorporated herein by reference.FIELD OF THE INVENTION [0002] The invention is related to container shipping and storage of produce, in particular, to the means for controlling the gas composition in such containers. BACKGROUND OF THE INVENTION [0003] Transfer of fruits in shipping containers necessitates a certain composition of a gas medium inside the container. That composition should change depending upon the type of fruits, the degree of their ripeness, and the technology for preparation of these fruits for sale. [0004] There are known inventions related to the systems for controlling gas media in shipping containers. [0005] U.S. Pat. No. 5,333,394, “Controlled atmosphere container system for perishable products”, Herdeman, et al., issued Aug. 2, 1994, includes a description of a system that is connected to the inlet connectin...

AI Technical Summary

Benefits of technology

[0009] The device described here achieves the required composition of the gas medium in a container for shipping and storage of produce—in particular, bananas—and constitutes a simple structure consuming a relatively small amount of energy.

[0012] Such a gas exchange process can be used to maintain a consistent composition of a gas medium in a container when, due to biological processes of the stored produce (e.g., respiration, ripening), the composition of the gas medium inside the container changes. Thus, to store bananas and to avoid their early ripening, it is necessary to maintain a reduced oxygen / increased CO2 gas medium (as compared to ambient air) inside the container. However, bananas respire during storage (take in oxygen and release CO2), which modifies the required conditions for storing them. In this case, the described device can be used for maintenance of a constant ratio of concentration of oxygen and CO2 inside the container. This is achieved by feeding oxygen from ambient air through a gas-permeable membrane, into the inner space of the gas exchange chamber, and feeding the CO2 from the gas exchange chamber through the membrane, into the ambient air. Determining a definite ratio of membrane permeability for CO2 and oxygen allows (due to the gas exchange developing in the chamber) to compensate for the modification of composition of the gas medium inside the container caused by banana respiration. As a result, it is possible to maintain the required ratio of oxygen and CO2 in the gas medium inside the container.

Problems solved by technology

However, bananas respire during storage (take in oxygen and release CO2), which modifies the required conditions for storing them.

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